Fix bad free in cgit_diff_tree

Since git commit 244c27242f44e6b88e3a381c90bde08d134c274b,

> diff.[ch]: have diff_free() call clear_pathspec(opts.pathspec)

calling diff_flush calls free(3) on opts.pathspec.items, so it can't
be a pointer to a stack variable.

1 files changed, 5 insertions, 7 deletions

@@ -341,9 +341,8 @@ void cgit_diff_tree(const struct object_id *old_oid,
                     filepair_fn fn, const char *prefix, int ignorews)
 {
         struct diff_options opt;
-        struct pathspec_item item;
+        struct pathspec_item *item;
 
-        memset(&item, 0, sizeof(item));
         diff_setup(&opt);
         opt.output_format = DIFF_FORMAT_CALLBACK;
         opt.detect_rename = 1;
@@ -354,10 +353,11 @@ void cgit_diff_tree(const struct object_id *old_oid,
         opt.format_callback = cgit_diff_tree_cb;
         opt.format_callback_data = fn;
         if (prefix) {
-                item.match = xstrdup(prefix);
-                item.len = strlen(prefix);
+                item = xcalloc(1, sizeof(*item));
+                item->match = xstrdup(prefix);
+                item->len = strlen(prefix);
                 opt.pathspec.nr = 1;
-                opt.pathspec.items = &item;
+                opt.pathspec.items = item;
         }
         diff_setup_done(&opt);
 
@@ -367,8 +367,6 @@ void cgit_diff_tree(const struct object_id *old_oid,
                 diff_root_tree_oid(new_oid, "", &opt);
         diffcore_std(&opt);
         diff_flush(&opt);
-
-        free(item.match);
 }
 
 void cgit_diff_commit(struct commit *commit, filepair_fn fn, const char *prefix)